Lab 5 - Projections

Having different map projections available is very significant because each projection shows a different type of view of an area. For example, equidistant map projections preserve distance proportions between longitudinal lines. So the vertical distance on the map is proportional to its counterpart on the ground. Also, an equal area map preserves the area of the entities represented in the map. Then there is a conformal map projection, which preserves angles. Without all three types of projections a person looking at a map will always have to adjust their direction according to margin of error produced by the projection. However, with the many different types of map projections, people are able to choose that map that best fits for the purpose it is being used for. Even though the map projections are useful in helping us understand the world spatially, there is also a problem that arises when attempting to read a map.

The reason different map projections are even needed is because they all give some sort of misrepresentation of the world. This problem comes from stretching a spherical figure on to a planar surface. That translation between shapes creates the phenomenon in which there are different levels of distortion shown on each map projection. In general, the central focus area of each map is the most accurate, and as the map moves away from the center the distortions increase. While the various map projections have different types of distortion, they all follow the same pattern where there are varying levels of distortion within the same map.

There is great potential for the advancement in mapping itself. As technology continues to become more advanced, map projection gains more potential to deliver more accurate and precise representations of the world. For example, in the gis map projection lab assignment, six different types of maps were used- for equidistant maps I used Conic and Plate Carree, for equal area maps I used Mollweide and Goode Homolosine, and for conformal maps I used Mercator and Stereographic- and every map gave a different measurement for the distance between two consistent points. A feature that is presented in ArcMaps is a Geographic Coordinate System, which allows the user to view a representation of the world that is based on a 3D spherical shape so it is not planar like the map projections. In the future, it is possible that there may be portable maps that are able to use the same 3D feature as on computers.

However, due to the unavoidable phenomenon of distorting a spherical image when trying to translate it to a planar surface, map projections will never be perfect. When using a paper map, the distortions in size, shape, and angles must be accounted for in order to have correct guidance from the map. Therefore, having knowledge of the different types of map projections, their inaccuracies, and levels of distortion will prove to be very helpful, and make using a map to navigate through any part of the world at least a little easier.